ANIMAL BEHAVIOR. 335 



usual restful state, with no further concern for the second egg. 

 The conduct varies considerably with different individuals. 



3. The Dovecot Pigeon. The dovecot pigeon behaves in a 

 similar way, but will generally try to get both eggs back ; and, 

 failing in this, she resigns the nest with more hesitation than 

 does the ring-neck. 



4. Results Considered. The passenger pigeon's instinct is 

 wound up to a high point of uniformity and promptness, and 

 her conduct is almost too blindly regular to be credited even 

 with that stupidity which implies a grain of intelligence. The 

 ring-neck's stupidity is satisfied with one egg. The dovecot 

 pigeon's stupidity may claim both eggs, but it is not always 

 up to that mark. 



In these three grades the advance is from extreme blind 

 uniformity of action, with little or no choice, to a stage of less 

 rigid uniformity, with the least bit of perplexity and a very 

 feeble, uncertain, dreamy sense of sameness between eggs in 

 and eggs out of the nest, which prompts the action of rolling 

 the eggs back into the nest. That is the instinctive way of 

 placing the eggs when in the nest, and the neck is only a 

 little further extended in drawing the eggs in from the out- 

 side. How very narrow is the difference between the ordinary 

 and the extraordinary act ! How little does the pendulum of 

 normal action have to swing beyond its usual limit ! 1 



But this little is in a forward direction, and we are in no 

 doubt as to the general character of the changes and the modi- 

 fying influences through which it has been made possible. 

 Under conditions of domestication the action of natural selec- 

 tion has been relaxed, with the result that the rigor of instinc- 

 tive coordinations which bars alternative action is more or less 



1 We come to equally surprising results in many different ways. Change the 

 position of the nest-box of the ring-neck, without otherwise disturbing bird, nest, 

 or contents, and the birds will have great difficulty in recognizing their nest, for 

 they know it only as something in a definite position in a fixed environment. If 

 a pair of these birds have a nest in a cage, and the cage be moved from one room 

 to another, or even a few feet from its original position in the same room, the 

 nest ceases to be the same thing to them, and they walk over the eggs or young 

 as if completely devoid of any acquaintance with or interest in them. Return 

 the cage to its original place and the birds know the nest and return to it at 

 once. 



